LOCATION FARVA OR
Established Series
Rev. RP/RHB/TDT
11/2025
FARVA SERIES
The Farva series consists of moderately deep, well drained soils formed in colluvium weathered from volcanic rocks. Farva soils are on mountains and have slopes of 3 to 70 percent. The mean annual precipitation is about 43 inches (1090 mm) and the mean annual air temperature is about 43 degrees F (6 degrees C).
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Typic Haploxerepts
TYPICAL PEDON: Farva very cobbly loam, forested. (Colors are for moist soil unless otherwise noted.)
Oi--0 to 0.5 inches (0 to 1 cm); litter from needles, leaves and twigs.
A--0.5 to 5 inches (1 to 14 cm); dark brown (7.5YR 3/2) very cobbly loam, brown (10YR 4/3) dry; moderate fine granular structure; soft, very friable, nonsticky and nonplastic; common medium and fine roots; many irregular pores; 25 percent cobbles; 20 percent gravel; slightly acid (pH 6.4); clear wavy boundary. (3 to 8 inches (8 to 20 cm) thick)
AB--5 to 12 inches (14 to 31 cm); dark brown (7.5YR 3/4) very cobbly loam, brown (7.5YR 4/4) dry; weak fine granular structure; soft, very friable, nonsticky and nonplastic; common medium and fine roots; many irregular pores; 25 percent cobbles, 20 percent gravel, 10 percent stones; slightly acid (pH 6.3); gradual wavy boundary. (0 to 10 inches (0 to 25 cm) thick)
Bw--12 to 27 inches (31 to 70 cm); brown (7.5YR 4/4) extremely cobbly loam, brown (7.5YR 5/4) dry; weak medium and fine subangular blocky structure; slightly hard, very friable, nonsticky and slightly plastic; few fine, medium and coarse roots; many fine tubular pores; 25 percent cobbles, 25 percent gravel, 15 percent stones; slightly acid (pH 6.2); gradual wavy boundary. (10 to 30 inches (25 to 76 cm) thick)
C--27 to 35 inches (70 to 90 cm); brown (7.5YR 4/4) extremely cobbly loam, brown (7.5YR 5/4) dry; massive; soft, very friable, nonsticky and nonplastic; few medium and coarse roots; many irregular pores; 35 percent cobbles, 20 percent gravel, 10 percent stones; moderately acid (pH 5.8); abrupt wavy boundary. (0 to 10 inches (0 to 25 cm) thick)
2Cr--35 inches (90 cm); partially weathered andesitic bedrock.
TYPE LOCATION: Jackson County, Oregon; 0.3 mile north of Hyatt Lake, 1,850 feet south and 700 feet east of the northwest corner of sec. 11, T. 39 S., R. 3 E., Willamette Meridian.
RANGE IN CHARACTERISTICS: Depth to a paralithic contact is 20 to 40 inches (50 to 100 cm). The particle-size control section averages 45 to 80 percent rock fragments, of which 5 to 20 percent are stones, 25 to 35 percent are cobbles, and 15 to 25 percent are gravel and it is 15 to 25 percent clay. The mean annual soil temperature is 42 to 47 degrees F (6 to 8 degrees C). The soil is usually moist, but is dry between 4 and 12 inches (10 to 30 cm) for 45 to 60 consecutive days or more in the four months following the summer solstice.
The A horizon has hue of 5YR, 7.5YR, or 10YR, value of 3 through 5 moist and 4 or 5 dry, and chroma of 2 through 4 moist and dry.
The B and C horizons have hue of 5YR or 7.5YR, value of 3 or 4 moist and 4 or 5 dry, and chroma of 3 or 4 moist and dry. It is extremely cobbly loam, or very cobbly loam.
COMPETING SERIES: These are the
Lostbasin and
Segundo series. Lostbasin soils have a lithic contact between 20 and 40 inches (50 to 100 cm). Segundo soils are more than 40 inches (100 cm) deep.
Heiners soils have a similar classification but have a paralithic contact within 20 inches (50 cm) of the mineral soil surface and are in a shallow family.
GEOGRAPHIC SETTING: Farva soils are on mountains at elevations of 3,600 to 6,100 feet (1090 to 1850 m). Slopes are 3 to 70 percent. The soils formed in colluvium weathered from andesite, tuffs and breccias. The mean annual air temperature is 40 to 45 degrees F (4 to 7 degrees C). The mean annual precipitation is 30 to 55 inches (760 to 1395 mm). The frost-free period is less than 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Bybee,
Kanutchan,
Pinehurst,
Sibannac and
Tatouche soils. Bybee, Kanutchan, and Tatouche soils are deep and fine. Sibannac soils are deep and poorly drained. The Pinehurst soils are fine-loamy, have a mollic epipedon over 20 inches (50 cm) thick and have an argillic horizon.
DRAINAGE AND PERMEABILITY: Well drained; medium and rapid runoff; moderately rapid permeability.
USE AND VEGETATION: Soils are used for timber production, grazing, water supply, recreation, and wildlife. Native vegetation dominantly is white fir, Douglas fir, shrubs, grasses, and forbs.
DISTRIBUTION AND EXTENT: Southern Cascades of southwestern Oregon. The soils are of moderate extent.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Jackson County Area, Oregon, 1988.
REMARKS:
Added metric depths and updated competing series11/2025. -JBB
National Cooperative Soil Survey
U.S.A.